Tobacco-manipulating machines



March 23, 1965 e. F. w. POWELL 3,174,486

TOBACCO-MANIPULATING MACHINES Filed May 9, 1961 2 Sheets-Sheet 1 lNl/EN OR ATTORNE)$ GQF. w. POWELL TOBACCO-MANIPULATING MACHINES 'j 2 Sheets-Sheet 2 Marc-h 23, 1965 Filed; May 9, I961 United States Patent 3,174,486 TOBACCO-MANIPULATING MAQHINES Gordon Francis Wellington Powell, Deptford, London,

England, assignor to Molins Machine Company Limited, a British company Filed May 9, 1961, Ser. No. 108,886 Claims priority, application Great Britain, May 10, 1960, 16,459/60 3 Claims. (Cl. 1331-84) This invention concerns improvements in or relating to tobacco manipulating machines, such as continuous rod cigarette making machines, in which a continuous stream of tobacco is formed and, While being conveyed lengthwise, the stream is trimmed to remove surplus tobacco therefrom.

' Henceforth in this specification the stream of tobacco before it is trimmed will be referred to as the filler stream and the portion of the tobacco stream remaining after trimming will be referred to as the filler.

In the specification and drawings of co-pending Patent No. 3,089,497 issued May 14, 1963, to D. W. Molins, et al. there is disclosed a tobacco manipulating machine in which a stream of tobacco is conveyed lengthwise on an air-pervious conveyor between opposed side walls which confine the tobacco laterally, air being passed through the stream and the conveyor to hold the stream suctionally thereto. Means are provided to detect variations in the pressure drop of the airflow through the stream, thereby to detect variations in the air permeability of the stream. The stream is conveyed past a trimming device which trims the stream to a desired depth by removing surplus tobacco. The trimming operation is controlled in accordance with said variations in the pressure drop to vary the amount of tobacco removed by varying the distance from the conveyor of the level at which the trimming device operates, thereby to remove, or at least to reduce, variations in the uniformity of the stream as indicated by said variations in the characteristic.

According to the present invention there is provided a tobacco-manipulating machine in which a continuous tobacco filler stream is conveyed lengthwise on an airpervious conveyor between opposed side walls which confine the tobacco laterally, air is passed through the tobacco stream and the conveyor to hold the stream thereto, variations in the pressure drop of the airflow through the stream are detected, and a trimming operation on the filler stream to remove the surplus tobacco in excess of that needed to form a cigarette rod is controlled in accordance with said variation, by-pass means being provided in the opposed side walls in the region where the air pressure is detected to admit air into the tobacco of the filler stream at or near the level where the surplus tobacco will be removed, whereby air flows through the surplus tobacco and the effect of variations in the quantity of surplus tobacco on the characteristic of the airflow is reduced.

The by-pass means may be a narrow slot in each opposed side wall, the slots extending in the direction of movement of the filler stream.

Where the trimming operation is controlled by varying the distance from the conveyor of the level at which a trimming device operates to remove the discard tobacco, the by-pass means may be provided at the greatest distance from the conveyor at which the trimming device operates.

The opposed walls may be recessed laterally to receive the discard portion of the filler stream and the by-pass means may be provided adjacent the edges of the recessed portions.

One embodiment of apparatus according to the inven- 3,l74,4 86 Patented Mar. 2 3, 1965 tion will now be described, by way of example, with ref= erence to the accompanying drawings, of which:

FIGURE 1 is a side elevation, partly in section of aportion of a continuous rod cigarette-making machine,

FIGURE 2 is a fragmentary view on the line 2--2 of FIGURE 1, and

FIGURE 3 is a fragmentary view similar to FIGURE 2 and showing a modification.

The apparatus corresponds closely with that shown in FIGURES 2 and 3 of the drawings of the hereinbefore mentioned patent.

In the machine illustrated in FIGURES 1 and 2, cut tobacco is fed by a high-velocity current of air to an air-pervious conveyor in the form of a perforated metal conveyor band 1 which runs through the upper part of a narrow passage within compartment 2 through which the air current flows upwardly. The tobacco so fed is suctionally held on the underside of the conveyor band 1, on which the tobacco builds up to form a continuous filler stream, by means of air drawn through the filler stream and conveyor band into a suction chamber 4. The filler stream is carried by the conveyor band 1 from right to left as shown in FIGURE 1 through a channel open to atmosphere and comprising opposed walls 9 which confine the tobacco laterally. A pipe 5 extends from the suction chamber 4 to air pumping means (not shown) which withdraw air from the suction chamber and maintain a pressure lower than atmospheric therein. Beyond the left end of the passage in compartment 2 as seen in FIG- URE 1, there is provided a trimming device 6 which trims the surplus from the filler stream to leave the filler on the conveyor band. The filler is transferred from the conveyor band 1 on to a continuous paper web 3 which forms the continuous paper wrapper which is folded over the filler to form the continuous cigarette rod. To prevent air from being drawn from atmosphere into the lefthand end of the top of the passage 2 and so disturb the tobacco filler, a wheel 30 is provided which carries flexible paddle elements 31. A housing 32 is provided which has a small clearance for the paddle elements 31 which are arranged in contact with the lower surface of the filler to rotate the wheel in the direction shown by the arrow. The wheel 39 and its mode of operation are more fully described in U.S. Serial No. 856,131, filed November 30, 1959, which has issued as Patent No. 3,091,244 on May 28, 1963.

The distance from the conveyor band 1 of the level at which the trimming device operates is varied in accordance with variations in the air permeability of the filler stream. A chamber 10 is provided above the conveyor band and has an opening 11 which is in communication with a length of the conveyor band 1 equal to less' than a cigarette length. A pipe 12 extends from the chamber 10 into the pipe 5 and terminates in this pipe so that air is drawn through the filler stream, the conveyor band, and the chamber 10 so that variations in pressure in the suction chamber 4 do not affect the suction pressure in chamber 10. Thus, depending on the air permeability of the length of filler stream at any instant below the chamber 10, the pressure in chamber 10 will vary and these variations provide an indication of variations in uniformity of the filler stream along its length. Disclosed and described fully in the hereinbefore mentioned patent are pneumatic and hydraulic means by means of which the trimming device 6 is moved towards and away from the band to vary the amount of surplus to remove or reduce variations in the uniformity of the filler stream. A pipe 13 conveys the pressure in chamber 10 to a bellows 20. The other end of the bellows moves up and down with variations in the air pressure therein and transmits this motion to the input member 21 of an hydraulic awaase servo device 22 by means of a lever 23. The output shaft of the servo device 22 is shown at 24 and has secured to it a member 240. A link 24b has its lower end pivotally connected to the right hand end of a lever 25 and its upper end pivotally connected to the member 24a. The left hand end of the lever 25 is arranged for movement up and down by manual adjustment of a knob 26. At its centre the lever 25 is pivotally connected to a link 27 which supports a housing 28 in which the trimming device 6 is mounted for rotation, The trimming de vice consists of two discs whose edges co-operate, but only one disc is shown here. Thus angular movement of the output shaft 24 causes up and down movement of the link 24b to pivot the lever 25 about its left-hand end and adjust the distance of the trimming discs 6 from the conveyor band 1. Thus the level at which the trimming device operates is controlled in accordance with variations in the pressure drop of the air passing through the tobacco filler stream into the chamber and the datum level of the trimming device is set by manual adjustment of the knob 26.

As shown in FIGURE 2, the channel comprising the opposed walls 9 for confining the tobacco laterally oetween the trimming device and the band 1, has concave recesses indicated with rounded sides 14 and an upper edge 14a communicating with opposed walls 9 on the opposite side of conveyor band 1 from the discs of the trimming device 6. As may be seen from FIGURE 1, the left end of recess 14 is in a position to receive surplus tobacco removed by the trimming device 6.

In the region below the chamber 10, the opposed walls 9 include by-pass means in the form of a slot in each wall which extend from the outer surface of each wall to its inner surface adjacent the edges 14a. Each slot is typically 67 mm. long in the direction of travel of conveyor band 1, and 3 mm. wide. The slots are just below the discs of the trimming device 6, as seen in FIG- URE 1, so that the portion of the tobacco filler stream which is retained on the conveyor band 1 after the trimming operation is above the slots 15, and the majority of the portion of the tobacco filler stream which is re-. moved by the trimming operation is below the slots 15. The slots 15 are parallel with the band 1.

The flow of air which is drawn through the filler stream, the conveyor band 1 and the chamber 10 enters the filler stream in two ways. Some of the air is drawn upwards between the concave recesses 14 and passes through the surplus portion ofthe filler stream into the filler portion thereof. The remainder of the air flows horizontally through the slots 15 into the filler portion, thus bypassing the surplus portion. Thus, as all the air flows through the filler portion and only some of the air fiows through the surplus portion, the variations in pressure in the chamber 10 will be more closely related to variations in air permeability of the filler portion caused by variations in density or compactness of the tobacco in the filler portion and less affected by variations in the quantity of the surplus than if all the air flowed through the surplus. Thus the variations in air pressure in the chamber 10 are more closely correlated with variations in uniformity of the filler stream and the trimming device will be controlled to produce a relatively uniform filler.

In FIGURE 3 there is shown a modification in which the by-pass means is in the form of slots 115 which are inclined upwards so that air flowing through the slots has to turn through less than a right angle to enter the tobacco. In this way eddying of the air is reduced and less resistance is offered to the airflow,

excess of tobacco over that required in said rod is formed and having an air-pervious conveyor to convey the tobacco filler stream in the direction of its length, opposed side walls between which the conveyor travels and which confine the filler laterally, the conveyor and the side walls forming an open channel, suction means to draw air through the open side of the channel and through the filler stream and the conveyor to press the filler stream against the conveyor, detecting means responsive to airflow through a predetermined length of the filler stream and the conveyor to detect variations occurring along the filler stream in the resistance to air flowing therethrough, trimming means located downstream of said predetermined length and spaced from the conveyor to separate and remove from the filler stream excess tobacco spaced further from the conveyor than the trimming means to produce a tobacco filler which is retained on the conveyor, control means responsive to the detecting means and operable on the trimming means to reduce the amount of tobacco removed by the trimming means from portions of the tobacco filler and including aperture defining means in each of the opposed side walls adjacent said predetermined length, said aperture defining means defining in each opposed side wall a narrow slot extending in the direction of travel of the filler stream and being spaced from the conveyor by substantially the same distance that the trimming means is spaced from the conveyor to admit air into the tobacco filler stream under the influence of the suction means to flow through that portion of the tobacco filler stream beween the aperture defining means and the conveyor, whereby additional air flows through said slots into the portion of the tobacco filler stream which is not removed by the trimming means.

2. A continuous rod cigarette making machine as claimed in claim 1 wherein the opposed side walls are recessed to receive the portion of the filler stream which is separated and removed by the trimming means, and the aperture defining means are provided adjacent the edges of the recessed portions.

3. A tobacco-manipulating machine as claimed in claim 1 wherein the slots are inclined towards the portion of the tiller stream not removed by the trimming means; so that air flowing through the slots has to turn through less than a right-angle to enter the tobacco.

References Cited by the Examiner UNITED STATES PATENTS 2,465,818 3/49 Richardson 13184 2,516,932 8/50 Wainwright 13121 2,617,426 11/52 Patterson 131-84 X 2,938,521 5/60 Lanore 13184 3,019,793 2/62 Labbe 131-84 3,026,878 3/62 Eissmann 131-1 10 X 3,031,883 5/62 Pocock et al. 1312l FOREIGN PATENTS 1,230,524 4/60 France.

764,551 12/56 Great Britain.

ABRAHAM G. STONE, Primary Examiner, JOSEPH S. REICH, Examiner. 

1. A CONTINUOUS ROD CIGARETTE MAKING MACHINE IN WHICH AN ELONGATED CONTINUOUS TOBACCO FILLER STREAM HAVING AN EXCESS OF TOBACCO OVER THE REQUIRED IN SAID ROD IS FORMED AND HAVING AN AIR-PERVIOUS CONVEYOR TO CONVEY THE TOBACCO FILLER STREAM IN THE DIRECTION OF ITS LENGTH, OPPOSED SIDE WALLS BETWEEN WHICH THE CONVEYOR TRAVELS AND WHICH CONFINE THE FILLER LATERALLY, THE CONVEYOR AND THE SIDE WALLS FORMING AN OPEN CHANNEL, SUCTION MEANS TO DRAW AIR THROUGH THE OPEN SIDE OF THE CHANNEL AND THROUGH THE FILLER STREAM AND THE CONVEYOR TO PRESS THE FILLER STEAM AGAINST THE CONVEYOR, DETECTING MEANS RESPONSIVE TO AIRFLOW THROUGH A PREDETERMINED LENGTH OF THE FILLER STREAM AND THE CONVEYOR TO DETECT VARIATIONS OCCURRING ALONG THE FILLER STREAM IN THE RESISTANCE TO AIR FLOWING THERETHROUGH, TRIMMING MEANS LOCATED DOWNSTREAM OF SAID PREDETERMINED LENGTH AND SPACED FROM THE CONVEYOR TO SEPARATE AND REMOVE FROM THE FILLER STREAM EXCESS TOBACCO SPACED FURTHER FROM THE CONVEYOR THAN THE TRIMMING MEANS TO PRODUCE A TOBACCO FILLER WHICH IS RETAINED ON THE CONVEYOR, CONTROL MEANS RESPONSIVE TO THE DETECTING MEANS AND OPERABLE ON THE TRIMMING MEANS TO REDUCE THE AMOUNT OF TOBACCO REMOVED BY THE TRIMMING MEANS FROM PORTIONS OF THE TOBACCO FILLER AND INCLUDING APERTURE DEFINING MEANS IN EACH OF THE OPPOSED SIDE WALLS ADJACENT SAID PREDETERMINED LENGTH, SAID APERTURE DEFINING MEANS DEFINING IN EACH OPPOSED SIDE WALL A NARROW SLOT EXTENDING IN THE DIRECTION OF TRAVEL OF THE FILLER STREAM AND BEING SPACED FROM THE CONVEYOR BY SUBSTANTIALLY THE SAME DISTANCE THAT THE TIMMING MEANS IS SPACED FROM THE CONVEYOR TO ADMIT AIR INTO THE TOBACCO FILLER STREAM UNDER THE INFLUENCE OF THE SUCTION MEANS TO FLOW THROUGH THAT PORTION OF THE TOBACCO FILLER STREAM BETWEEN THE APERTURE DEFINING MEANS AND THE CONVEYOR, WHEREBY ADDITIONAL AIR FLOWS THROUGH SAID SLOTS INTO THE PORTION OF THE TOBACCO FILLER STREAM WHICH IS NOT REMOVED BY THE TRIMMING MEANS. 